A terrible death, not fast or humane.
Science needs to get on this with some kind of metronidazole like water treatment.
There’s not much that can be done except avoid getting the water in your nose. That’s how it gets into the body.............
https://www.uswatersystems.com/blog/2013/10/brain-eating-amoeba/
Nose plugs or clips is about all you can do besides staying out of the water altogether.
Here in Florida, we have ‘Flesh Eating Bacteria’ that can infect open wounds, sores and scratches on people who get in warm waters that are infested..................